Avalanche Forecast

Issued: Mar 14th, 2013 9:11AM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Storm Slabs, Cornices and Wind Slabs.

Alberta Parks burke.duncan, Alberta Parks

Another warm storm system has added another layer of snow that is readily available for slab development. Anticipate changing conditions and be prepared for a variety of traveling conditions. Stepping down is a possibility as well.

Summary

Confidence

Good

Weather Forecast

Temps are expected to cool off in the alpine by 5 degrees but remain around 0 for TL elevations(1500m). No precip is expected and winds are still forecasted to be strong to extreme. Another round of precip is expected to arrive Sunday. How this interacts with the existing snow will remain to be seen.

Avalanche Summary

No avalanches noted today, observations very limited due to poor vis. Bombing runs in neighboring areas triggered one notable Sz3 slab (E asp, 2300m). Cornices were reportedly very large as well.

Snowpack Summary

Inversion conditions today led to moist snow starting at 2000m. Rain crust on surface below that. Limited visibility today, but storm slabs from the ongoing wind event are certain at TL & ALP elevations. These slabs will remain reactive to human triggering in steep terrain at all elevations until the temperatures cool. The warm nature of the storm will promote slab development and cornice growth.

Problems

Storm Slabs

An icon showing Storm Slabs
New storm slabs are developing along ridgetops at treeline and above.  A combination of above freezing temperatures, moist snow and rainfall up to 2100m will result in rapid slab formation.
Avoid freshly wind loaded features.>Avoid cross loaded slopes at or above treeline.>

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 5

Cornices

An icon showing Cornices
Alpine ridges
Avoid areas with overhead hazard.>Stay well back from cornices.>

Aspects: North, North East, East, South East, South.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Wind Slabs

An icon showing Wind Slabs
Soft slabs and hard slabs are widespread in alpine and treeline areas. Natural avalanche activity has significantly reduced, but skier-triggering is possible in steep, convex and/or unsupported terrain.
Avoid convexities or areas with a thin or variable snowpack.>

Aspects: North, North East, East, South East.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 5

Valid until: Mar 15th, 2013 2:00PM